The present invention relates to supply circuits of electrical networks, and more particularly to charge-discharge current stabilizers for storage batteries.
The problem of stabilizing a charge-discharge current in the process of manufacturing storage batteries consists in that the majority of types of the up-to-date storage batteries are used under different operating conditions with the discharge current being changed by several orders within one cycle which brings about a necessity to test storage batteries under analogous operating conditions in the process of manufacturing thereof. It should be noted that during check tests each storage battery is discharged to the voltage of order of 1 V after which it is cut out of the circuit.
In such a case heavy current surges occur in the circuit, while in charging and discharging the storage batteries the current in the circuit changes monotonously. For this purpose it is necessary to insert into the charge-discharge circuit a stabilizer being substantially sensitive to monotonous variations of the current and quickly responding to heavy surges of the current in the circuit. Since the majority of stabilizers possess no such features, can operate within a narrow current range, are intricate in design and unreliable in operation, in the process of manufacturing use is generally made of rectifiers provided with manually-controlled slide-type current regulators.
Known in the art is an automatic device stabilizing the charge-discharge current for storage batteries (see the USSR Inventor's Certificate No. 164,354; published in Bulletin "Discoveries, Inventions, Industrial Designs and Trademarks" No. 15, 1964), comprising a transformer having an elongated core which mounts a stationary winding and a movable winding. Current stabilization in such a device is performed by an electrodynamic action of the transformer movable winding reactance which varies in magnitude with the winding being displaced over the core. The range of the stabilized current in this case may be set up within narrow limits only by way of changing the weight of the movable winding due to which such stabilizers are only used on the special stands for forming similar storage batteries under the same operating conditions. Moreover, such stabilizers have a low efficiency, as about 20% of electric energy is spent for producing the dynamic effect of stabilization.
Also known in the art are stabilizers having a pulse-phase system of rectifier electronic control. The closest to the proposed apparatus is a charge-discharge current stabilizer for storage batteries (see USSR Inventor's Certificate No. 372,604; published in Bulletin "Discoveries, Inventions, Industrial Designs and Trademarks" No. 13, 1973), comprising a rectifier with a control element, connected in series with a switch and storage batteries into a charge-discharge circuit, and a rectifier control system having a current setter and a current sensor incorporated into the charge-discharge circuit.
The rectifier control system in this stabilizer is essentially a pulse-phase system having a control transistor, a DC amplifier, filters, a reference voltage source and a thyristor rectifier.
The rectifier control pulse-phase system fails to provide a sufficiently wide range of the stabilized current inasmuch as the stabilization limits are restricted by the performances of electronic control elements. Therefore, manufacturers of storage batteries should have a great variety of stands for testing the storage batteries under different operating conditions with respect to the current.